linux-kernel - [PATCH 0/3] tools/testing: expand mremap testing

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <cover.1753119043.git.lorenzo.stoakes@oracle.com>
Date: Mon, 21 Jul 2025 18:33:24 +0100
From: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: "Liam R . Howlett" <Liam.Howlett@...cle.com>,
        Vlastimil Babka <vbabka@...e.cz>, Jann Horn <jannh@...gle.com>,
        Pedro Falcato <pfalcato@...e.de>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 0/3] tools/testing: expand mremap testing

Expand our mremap() testing to further assert that behaviour is as
expected.

There is a poorly documented mremap() feature whereby it is possible to
mremap() multiple VMAs (even with gaps) when shrinking, as long as the
resultant shrunk range spans only a single VMA.

So we start by asserting this behaviour functions correctly both with an
in-place shrink and a shrink/move.

Next, we further test the newly introduced ability to mremap() multiple
VMAs when performing a MAP_FIXED move (that is without the size being
changed), firstly by asserting that MREMAP_DONTUNMAP has no bearing on this
behaviour.

Finally, we explicitly test that such moves, when splitting source VMAs,
function correctly.

Lorenzo Stoakes (3):
  tools/testing/selftests: add mremap() shrink test for multiple VMAs
  tools/testing/selftests: test MREMAP_DONTUNMAP on multiple VMA move
  tools/testing/selftests: explicitly test split multi VMA mremap move

 tools/testing/selftests/mm/mremap_test.c | 235 ++++++++++++++++++++++-
 1 file changed, 225 insertions(+), 10 deletions(-)

--
2.50.1